A sweeping analysis of 384 studies covering almost every major investigation into vaping among people under 25 has found that adolescents and young adults who use e-cigarettes are about three times more likely to take up conventional smoking later on. Published in the journal Tobacco Control and led by Professor Su Golder of the University of York, the review also links youth vaping to sharply higher odds of cannabis use, binge drinking, asthma, cough and mental-health problems, including suicidal thoughts. The findings intensify pressure on regulators already struggling to curb the growing popularity of flavoured, disposable devices. In France, a national ban on single-use “puffs” that took effect on 25 February has so far failed to drive the products from the market. Consumer-protection inspectors have detected illicit sales in bricks-and-mortar shops and online platforms, with devices still available for €10–€15 and providing up to 9,000 inhalations—roughly the nicotine content of 300 cigarettes. One fifth of French middle-school pupils and almost half of high-school students had tried vaping by 2022, according to the national drug-monitoring agency. US authorities are confronting a similar influx. The Food and Drug Administration and Customs and Border Protection recently confiscated some US$34 million worth of unapproved e-cigarettes in Chicago and say joint operations have netted 7.1 million devices—valued at more than US$136 million—over the past two years. Many of the seized shipments had been declared as ordinary consumer goods such as shoes or toys. Public-health officials remain divided over how to balance vaping’s potential role in smoking cessation for adults against the risks identified for teenagers. A 2018 review by Public Health England concluded that e-cigarettes are 95 percent less harmful than traditional smoking and do not entice youth into tobacco use, a position now at odds with the new evidence base. The latest study and enforcement data are likely to fuel calls across Europe and the United States for tighter age checks, flavour restrictions and stronger policing of the fast-growing illicit market.